Zipper Component and Slide Zipper, and Method for Producing Zipper Component

ABSTRACT

A zipper component includes a metal plating film provided on the surface of a component body made of a metal. Further, in the zipper component, at least a part of the component body has been thermally treated before bending and thus the metal plating film has a recrystallized structure wherein at least a part of the metal plating film been recrystallized. Accordingly, since the ductility of the metal plating film can be improved, even when the zipper component is bent, the metal plating film can be deformed to follow the deformation of the component body. Therefore, the occurrence of crevicing or cracking in the metal plating film can be prevented.

TECHNICAL FIELD

The invention relates to a zipper component for a slide zipper, at leasta part of which is subjected to bending, such as caulking and the like,and a method for producing the same, and more specifically, to a zippercomponent including a component body made of a metal and a metal platingfilm provided on the surface of the component body and a method forproducing the same.

BACKGROUND ART

In general, various zipper components such as an opening-type separablebottom end stop such as a zipper element, an upper stopper, a lowerstopper, an insert pin, a box pin and the like, and a slider are usedfor a slide zipper, and components made of a metal are variouslyincluded in these zipper components.

One of the zipper components made of a metal is a zipper element. Ingeneral, the zipper element made of a metal has a coupling head and thelike formed by subjecting a plate material made of a metal such as, forexample, copper, a copper alloy and the like, which has a predeterminedthickness to press molding, and is formed by punching the platematerial, and the like so as to have an approximately Y-shape. Further,the zipper element made of a metal obtained is mounted on a zipper tapeby caulking the right and left leg portions toward the inner side ofboth the leg portions while the zipper tape is interposed between theright and left leg portions.

In addition, the lower stopper of a metal as one of the other zippercomponents is described in, for example, U.S. Pat. No. 2,884,691 (PatentDocument 1). The lower stopper described in Patent Document 1 is formedby subjecting a metal wire having a circular cross-section to rollingprocessing, deforming the cross-section of the metal wire into anapproximately X-shape (or an approximately H-shape), and then cuttingthe metal wire into a predetermined length. Furthermore, the lowerstopper having an approximately X-shape (or approximately H-shape)cross-section obtained is mounted on the zipper tape by caulking a pairof arm portions extended to the left and right, respectively, toward thezipper tape.

Further, a zipper component such as an upper stopper, an insert pin, abox pin and the like, of a metal is also mounted on the zipper tape bymolding or cutting a metal material such as copper, a copper alloy, analuminum alloy, a zinc alloy and the like into a predetermined shape andthen subjecting the zipper component obtained to caulking.

Meanwhile, in the case of a slider made of a metal, a slider body and atab having a predetermined shape are formed by performing a die-castmolding using a metal such as, for example, an zinc alloy, an aluminumalloy and the like, and the tab may be mounted on the slider body insome cases by subjecting a part of the slider body obtained to caulkingor bending.

PRIOR ART DOCUMENT Patent Document

-   Patent Document 1: U.S. Pat. No. 2,884,691

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

In the related art, for a product made of a metal, a metal plating filmis formed on the surface of the product by subjecting the product toplating treatment for the purpose of imparting new design, improvingcorrosion resistance and the like. The formation of the metal platingfilm has been often performed on zipper components made of variousmetals, which constitute a slide zipper, in the related art.

For example, for a zipper component such as a zipper element, upper andlower stoppers and the like made of a metal such as copper, acopper-alloy, and the like, a metal plating film made of acopper-zinc-based alloy (brass), or a white-system metal plating filmmade of a copper-tin-based alloy or a tin-nickel-based alloy is formedon the surface of the zipper component in order to protect a componentbody, which is a base material or impart a desired color tone.

In addition, for example, for a zipper component such as a zipperelement or upper and lower stoppers using a metal such as an aluminumalloy and the like as a matrix, upper and lower stoppers or a sliderusing a metal such as a zinc alloy and the like as a matrix and thelike, a metal plating film made of copper (pure copper) or acopper-zinc-based alloy may be formed on the surface of the componentbody, for the purpose of imparting a desired color tone or improvingcorrosion resistance.

However, the metal plating film made of a metal described abovegenerally has a high hardness. For this reason, for example, in order toform a metal plating film on a zipper component such as a zipperelement, upper and lower stoppers and the like, and then mount a zippercomponent having the metal plating film on a zipper tape, or in order tomount a tab on a slider body, when bending such as caulking and the likeas described above is performed, crevicing or cracking is easily formedin the metal plating film, which is considered defective.

When crevicing or cracking is formed in a metal plating film in thismanner, a base material is exposed from the portion on which thecrevicing or cracking occurs even though the metal plating film isformed in order to impart a desired color tone, and thus the zippercomponent is visually deteriorated, thereby damaging the design orappearance quality of the slide zipper, which is problematic.

Furthermore, when a metal plating film is formed on the surface of thezipper component for the purpose of improving corrosion resistance,corrosion easily occurs in the base material (matrix) of the zippercomponent from the portion on which crevicing or cracking occurs, whichis problematic.

In particular, recently, in order to allow a product to be fastened, onwhich a slide zipper is used, to provide an aesthetic appearance, abig-size zipper element, upper and lower stoppers and the like, whichlook flat, have been used in the slide zipper. However, when thebig-size zipper element or upper and lower stoppers are caulked on azipper tape, the deformation volume of the plastic deformation due tothe caulking is so large that crevicing or cracking significantly occursin the metal plating film, and because the size of crevicing or crackingis increased and the like, a visual problem or a corrosion problem ofthe zipper component as described above is further deteriorated.

The invention has been made in view of the problems in the related art,and the specific object of the invention is to provide a zippercomponent on which crevicing or cracking is less likely to occur in themetal plating film formed on the surface of the component body eventhough the zipper component is bent, a slide zipper in which the zippercomponent is bent and used, and a method for producing the zippercomponent.

Means for Solving the Problems

In order to achieve the object, the zipper component provided by theinvention is, as a basic constitution, a zipper component for a slidezipper in which a metal plating film is formed on the surface of acomponent body made of a metal and at least a part of the component bodyafter the formation of the metal plating film is subjected to bending. Athermal treatment is performed before the bending, and thus the metalplating film has a recrystallized structure wherein at least a part ofthe crystal structure has been recrystallized.

In particular, in the zipper component according to the invention, therecrysallized structure is preferably formed by forming the metalplating film as a columnar crystal structure on the surface of thecomponent body, and then subjecting the metal plating film to thethermal treatment to recrystallize at least a part of the columnarcrystal structure.

In the zipper component according to the invention, the component bodyis preferably made of copper or a copper-zinc-based alloy. In this case,the component body particularly preferably contains copper in an amountof at least from 75 wt % to 100 wt % and zinc in an amount of from 0 wt% to 25 wt %.

Further, in the zipper component according to the invention, thecomponent body may have a metal body made of zinc or a zinc-based alloyand a base plating film, which is provided on the surface of the metalbody and made of copper. Otherwise, the component body may have a metalbody made of an aluminum-based alloy, a first base plating film, whichis provided on the surface of the metal body and made of zinc, and asecond base plating film, which is provided on the surface of the firstbase plating film and made of copper.

In addition, in the zipper component according to the invention, themetal plating film is preferably made of at least one selected from thegroup consisting of a copper-zinc-based alloy, a copper-tin-based alloy,and a tin-nickel-based alloy.

In the zipper component of the invention, the metal plating film havingthe recrystallized structure has a film thickness of preferably from 1μm to 10 μm.

Further, the metal plating film having the recrystallized structure hasa Vickers hardness of preferably from Hv50 to Hv100.

In addition, a surface layer portion on the metal plating film side ofthe component body preferably has a diffusion layer formed by diffusinga metal included in the metal plating from.

Furthermore, the zipper component is preferably at least one componentselected from the group consisting of a zipper element, a stopper, anopening-type separable bottom end stop, and a slider.

Further, according to the invention, a slide zipper in which a zippercomponent having the constitution is bent and used may be provided.

In addition, a method for producing the zipper component provided by theinvention is, as a basic constitution, a method for producing a zippercomponent for a slide zipper, by which a metal plating film is providedon the surface of a component body made of a metal and at least a partof the component body is bent after the metal plating film is formed,and the method includes forming the metal plating film on the surface ofthe component body and subjecting the metal plating film to thermaltreatment at a temperature which is equal to or more than therecrystallized temperature to form a recrystallized structure wherein atleast a part of the crystal structure of the metal plating film has beencrystallized.

In particular, the method for producing a zipper component according tothe invention preferably includes forming the metal plating film whichis provided on the surface of the component body as a columnar crystalstructure and forming the recrystallized structure by subjecting themetal plating film having the columnar crystal structure to the thermaltreatment.

The method for producing a zipper component according to the inventionpreferably includes allowing the metal plating film to be made of acopper-zinc-based alloy and heating the metal plating film at from 300°C. to 400° C. with the heat treatment.

Further, the method for producing a zipper component according to theinvention may include allowing the metal plating film to be made of acopper-tin-based alloy and heating the metal plating film at from 400°C. to 500° C. with the heat treatment. Otherwise, the production methodof the invention may include allowing the metal plating film to be madeof a tin-nickel-based alloy and heating the metal plating film at from500° C. to 600° C. with the heat treatment.

In addition, the production method of the invention preferably includescontrolling the Vickers hardness of Hv120 or more, which the metalplating film has, to from Hv50 to Hv100, by the thermal treatment.

Effect of the Invention

In the zipper component according to the invention, a metal plating filmis formed on the surface of a component body made of a metal, and thenthe metal plating film is thermally treated. Accordingly, the metalplating film formed on the zipper component has a recrystallizedstructure wherein at least a part of the crystal structure has beenrecrystallized.

Since at least a part of the metal plating film has a recrystallizedstructure in this manner and the metal plating film has better ductilitythan the metal plating film formed on the surface of the component bodybefore the thermal treatment, the metal plating film may be elongatedrelatively readily, and crevicing or cracking on the metal plating filmmay be less likely to occur.

Accordingly, in the case of the zipper component of the invention, whena component body including a metal plating film provided on the surfaceof the component body as described above is bent, the metal plating filmmay be readily deformed to follow the deformation of the component body,and thereby making it difficult or impossible to generate crevicing orcracking in the metal plating film.

For this reason, the zipper component may solve a problem caused bycrevicing or cracking in the metal plating film in the zipper componentin the related art, that is, a problem that the zipper component isvisually deteriorated, and a color imparted to the metal plating filmmay be uniformly obtained. In addition, the zipper component may readilysolve a problem in the related art that corrosion easily occurs on thebase material of the zipper component.

In particular, in the zipper component according to the invention, therecrystallized structure is formed by forming a metal plating film as acolumnar crystal structure on the surface of a component body, and thensubjecting the metal plating film to thermal treatment to recrystallizeat least a part of the columnar crystal structure. The invention may beparticularly suitably applied when the metal plating film is grown as acolumnar crystal structure.

That is, the zipper component of the invention with at least a part ofthe metal plating film having a columnar crystal structurerecrystallized has excellent ductility, compared to the metal platingfilm in the related art, having only a columnar crystal structure. Forthis reason, this may make it difficult to generate crevicing orcracking in the metal plating film formed on the zipper component.

The zipper component of the invention may be suitably applied when thecomponent body is made of copper or a copper-zinc-based alloy. Sincecopper or the copper-zinc-based alloy has excellent ductility, bendingsuch as caulking and the like may be relatively readily performed, andcopper or the copper-zinc-based alloy has been often used in the relatedart, for example, as a material for the zipper component such as azipper element, upper and lower stoppers and the like. If a metalplating film having a recrystallized structure is provided on thesurface of the zipper component made of copper or a copper-zinc-basedalloy, the occurrence of crevicing or cracking in the metal plating filmmay be effectively prevented when the component body is bent.

Particularly in this case, the component body may contain copper in anamount of at least from 75 wt % to 100 wt % and zinc in an amount offrom 0 wt % to 25 wt % to more securely prevent the occurrence of stresscorrosion crevicing in the component body which has been subjected tobending.

Further, the zipper component of the invention may be suitably appliedeven when the component body has a metal body made of zinc or azinc-based alloy and a base plating film which is provided on thesurface of the metal body and made of copper. Zinc has generally lowcosts and may also be readily formed into a desired shape by using adie-cast molding, and thus has been conveniently used as a material forthe zipper component such as, for example, an opening-type separablebottom end stop, a slider and the like. In addition, since zinc has lowcorrosion resistance, a base plating film made of copper havingexcellent corrosion resistance is formed on the surface of the metalbody when zinc or a zinc-based alloy is used as a metal matrix.

Even when a metal plating film having a recrystallized structure isprovided on the surface of the zipper component having the metal bodymade of copper or a copper-zinc-based alloy and the base plating film,the occurrence of crevicing or cracking in the metal plating film may beeffectively prevented when the component body is bent.

In addition, the zipper component of the invention may be suitablyapplied even when the component body has a metal body made of analuminum-based alloy, a first base plating film which is provided on thesurface of the metal body and made of zinc, and a second base platingfilm which is provided on the surface of the first base plating film andmade of copper.

The aluminum-based alloy is lightweight. For this reason, a zippercomponent made of a metal may be very lightly constructed by using analuminum-based alloy as a metal matrix of the zipper component.Accordingly, the aluminum-based alloy has been conveniently used as amaterial for a zipper component such as a zipper element, upper andlower stoppers, a slider and the like.

Furthermore, the aluminum-based alloy also has low corrosion resistance,and thus when the aluminum-based alloy is used as a metal matrix, afirst base plating film made of zinc is formed on the surface of themetal body by electroless plating and the like, and a second baseplating film made of copper having excellent corrosion resistance isalso formed on the surface of the first base plating film.

Even when a metal plating film having a recrystallized structure isprovided on the surface of the zipper component having the metal bodymade of the aluminum-based alloy and the first and second base platingfilms, the occurrence of crevicing or cracking in the metal plating filmmay be effectively prevented when the component body is bent.

Further, in the zipper component of the invention, a material for themetal plating film may use, for example, copper (pure copper), acopper-zinc-based alloy and a white system metal (for example, acopper-tin-based alloy, a tin-nickel-based alloy, nickel, chromium,vanadium, rhodium, platinum and the like), and in particular, the metalplating film in the invention is preferably made of at least oneselected from the group consisting of a copper-zinc-based alloy, acopper-tin-based alloy and a tin-nickel-based alloy, which have arelatively low recrystallized temperature region. The metal plating filmmade of the material may have a recrystallized structure to prevent theoccurrence of crevicing or cracking in the metal plating film even whenthe zipper component is bent, and thus the zipper component may obtain agood appearance quality.

In addition, in the zipper component of the invention, the metal platingfilm having a recrystallized structure has a film thickness of from 1 μmto 10 μm and preferably from 2 μm to 6 μm. A metal plating film may bestably and securely formed by setting the film thickness of the metalplating film to 1 μm or more (preferably 2 μm or more).

Furthermore, the thicker the film thickness of the metal plating film isformed, the better the metal plating film may be stably formed. However,although the film thickness of the metal plating film is set at morethan 10 μm, the effect that the metal plating film has been stabilizedor the appearance quality obtained by the metal plating film has beenimproved is not changed very much, and thus the film thickness of themetal plating film is set at 10 μm or less (preferably 6 μm or less).

Further, in the zipper component of the invention, the metal platingfilm having a recrystallized structure has a Vickers hardness of fromHv50 to Hv100. When the Vickers hardness of the metal plating film isHv50 or more, the occurrence of scratch and the like may be prevented onthe surface of the zipper component to maintain a good appearancequality.

Meanwhile, when the Vickers hardness of the metal plating film is Hv100or less, the metal plating film may, be relatively smoothly formed toimprove the ductility of the metal plating film. For this reason, whenthe zipper component is bent, even in the case where the volume of theplastic deformation in the component body of the zipper component due tothe bending is large; the occurrence of crevicing or cracking in themetal plating film may be more securely prevented.

In addition, in the zipper component of the invention, a surface layerportion on the metal plating film side of the component body has adiffusion layer formed by diffusing a metal included in the metalplating film. The adhesiveness of a metal plating film on the componentbody may be improved by having the diffusion layer on the surface layerportion of the component body to allow the metal plating film to havegood affinity to the component body.

The zipper component of the invention is particularly suitably appliedto an opening-type separable bottom end stop such as, for example, azipper element, an upper stopper, a lower stopper, an insert pin, a boxpin, and the like and a part such as a slider.

Moreover, the slide zipper provided by the invention is configured bybending the zipper component having the above-described configuration tobe used. Therefore, since the slide zipper of the invention has nooccurrence (or very few occurrence) of crevicing or cracking in themetal plating film of the zipper component, the zipper component hasuniform color, and thus a slide zipper, which is visually improved andhas excellent design or appearance quality, is obtained.

Subsequently, the method for producing a zipper component provided bythe invention includes forming a metal plating film on the surface of acomponent body of the zipper component and producing the zippercomponent by subjecting the metal plating film to thermal treatment at atemperature which is equivalent or more than the recrystallizedtemperature before bending.

According to the production method of the invention, the crystalstructure of the metal plating film is recrystallized by subjecting ametal plating film which is provided on the surface of the componentbody to thermal treatment, and thus a metal plating film having at leastapart of a recrystallized structure in which the crystal orientation isdisturbed may be readily formed. Since the metal plating film having therecrystallized structure in this way has improved ductility, theoccurrence of crevicing or cracking in the metal plating film may beeffectively prevented when the zipper component produced by theproduction method is bent.

In particular, in the method for producing a zipper component accordingto the invention, a metal plating film provided on the surface of thecomponent body is formed as a columnar crystal structure and arecrystallized structure is formed by subjecting the metal plating filmhaving the columnar crystal structure to thermal treatment. In this way,the invention may be particularly suitably applied when the metalplating film is grown as a columnar crystal structure. That is, theductility of the metal plating film may be improved by subjecting themetal plating film formed as a columnar crystal structure to thermaltreatment, thereby making it difficult to generate crevicing or crackingin the metal plating film after the thermal treatment.

Furthermore, in the production method of the zipper component accordingto the invention, the metal plating film is made of a copper-zinc-basedalloy and heated to a temperature of from 300° C. to 400° C. by thermaltreatment. Accordingly, when the metal plating film is made of acopper-zinc-based alloy, a recrystallized structure may be readily andstably formed in at least a part of the metal plating film.

Further, in the production method of the zipper component according tothe invention, the metal plating film is made of a copper-tin-basedalloy, and the metal plating film is heated to a temperature of from400° C. to 500° C. by thermal treatment. Accordingly, when the metalplating film is made of a copper-tin-based alloy, a recrystallizedstructure may be readily and stably formed in at least a part of themetal plating film.

In addition, in the method for producing a zipper component according tothe invention, the metal plating film is made of a tin-nickel-basedalloy, and the metal plating film is heated to a temperature of from500° C. to 600° C. by thermal treatment. Accordingly, when the metalplating film is made of a tin-nickel-based alloy, a recrystallizedstructure may be readily and stably formed in at least a part of themetal plating film.

Furthermore, in the production method of the invention, the Vickershardness of Hv120 or more, which the metal plating film has, iscontrolled to a value from Hv50 to Hv100 by the thermal treatment. Theoccurrence of scratch and the like may be prevented on the surface ofthe zipper component and a good appearance quality may be maintained bycontrolling the Vickers hardness of the metal plating film to Hv50 ormore. Meanwhile, by controlling the Vickers hardness of the metalplating film to Hv100 or less, the occurrence of crevicing or crackingin the metal plating film may be even more securely prevented when thezipper component is bent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view schematically illustrating across-section of a zipper component before thermal treatment.

FIG. 2 is a cross-sectional view schematically illustrating across-section of a zipper component after thermal treatment.

FIG. 3 is a front view illustrating a zipper component constituting aslide zipper.

FIG. 4 is a cross-sectional view illustrating a lower stopper.

FIG. 5 is an explanatory view schematically illustrating bending of alower stopper against a zipper tape.

FIG. 6 is a flowchart for explaining a method for producing a zippercomponent according to embodiments of the invention.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferable embodiments of the invention will be describedin detail with reference to the drawings. Further, the invention is notlimited to embodiments to be described below, and various modificationscan be made as long as the embodiments have a configuration which issubstantially equivalent to the configuration of the invention and showthe same operational effects.

Herein, FIG. 1 is a cross-sectional view schematically illustrating astate before a zipper component with a metal plating film formed on thesurface of a component body is subjected to thermal treatment, and FIG.2 is a cross-sectional view schematically illustrating a state after thezipper component is thermally treated.

A zipper component 1 according to the embodiment is a component in whichthe matrix of a component body 2 is made of a metal and at least a partof the component body 2 is subjected to bending, such as caulking andthe like, among the components constituting the slide zipper. Forexample, as a general slide zipper 10 is shown in FIG. 3, the zippercomponent 1 includes a metal zipper element 11, a lower stopper 12, anupper stopper 13, a slider 14 (in particular, a slider body), an insertpin which is not shown, a box pin which is not shown and the like.

The metal zipper element 11 is generally produced by, sequentiallycutting a long metal wire having a Y-shaped cross-section into a desiredthickness in the longitudinal direction to form an element materialhaving a Y-shape when viewed from the front face, subjecting the elementmaterial to press molding to form a coupling head, or subjecting a platematerial made of a metal such as copper, a copper alloy and the like,having a predetermined thickness, to press molding to form a couplinghead and the like, and punching the plate material.

The metal zipper element 11 thus-produced is mounted on a zipper tape 15by bending both the leg portions to plastically deform both the legportions in the direction in which both the leg portions approach eachother in a state where the zipper tape 15 having a core thread portion15 a is interposed between both the leg portions, which are extended tobe disposed in a fork shape from the coupling head.

The lower stopper 12 is generally produced by sequentially cutting along metal wire having an X-shaped or H-shaped cross section into adesired thickness in the longitudinal direction. In the lower stopper 12having the X-shaped or H-shaped cross section, first, each of the leftand right zipper tapes 15 having the core thread portion 15 a isinserted between a group of arm portions 12 b extending in the left andright directions from a body portion 12 a, as shown in FIG. 4. Moreover,the lower stopper 12 is mounted across the left and right zipper tapes15 by performing bending to plastically deform each group of the armportions 12 b in the direction in which the groups of the arm portions12 b approaches each other in a state where the zipper tape 15 isinterposed between each group of the arm portions 12 b.

The upper stopper 13 is generally produced by sequentially cutting along metal wire having a U-shaped cross section into a desired thicknessin the longitudinal direction, or sequentially cutting a metal wirehaving a plate shape into a desired thickness in the longitudinaldirection and bending a cut fragment obtained into a U-shape. For theupper stopper 13 having the U-shaped cross section, the upper stopper 13is mounted on the zipper tape 15 by performing bending to plasticallydeform both the end portions of the upper stopper 13 in the direction inwhich both the end portions of the upper stopper 13 approaches eachother in a state where the zipper tape 15 is interposed between both theend portions of the upper stopper 13.

The slider 14, the insert pin and the box pin are generally produced byperforming a die-cast molding using a metal mold having a predeterminedcavity shape. For example, a slider body and a tab are molded bysubjecting the slider 14 to a die-cast molding. In addition, the tab ismounted on the slider body by bending a part of the slider body in astate where the tab is supported on a part of the slider body.Meanwhile, the insert pin and the box pin are produced by a die-castmolding and then mounted on the zipper tape by performing bending.

The zipper component 1 according to the present embodiment, includingthe metal zipper element 11, the lower stopper 12 and the like asdescribed above, has a component body 2 made of a metal and a metalplating film 3 provided on the surface of the component body 2, and asdescribed below, the zipper component 1 is subjected to thermaltreatment which recrystallizes the crystal structure of the metalplating film 3, and then a diffusion layer 4 is formed on the surfacelayer portion of the component body 2.

A metal material that constitutes the component body 2 is notparticularly limited. However, since the zipper component 1 of theembodiment is a component that constitutes a slide zipper as describedabove and at least a part of the zipper component 1 is bent, a metalmatrix of the component body 2 is preferably at least one metal selectedfrom the group consisting of copper, a copper-zinc-based alloy, zinc, azinc-based alloy and an aluminum-based alloy.

In particular, when the metal matrix of the component body 2 is made ofcopper or a copper-zinc-based alloy, the component body 2 has excellentductility, and thus bending such as caulking and the like may berelatively readily performed. In addition, in this case, the higher theratio of copper ingredients included in the component body 2 (metalbody) is, the better ductility or corrosion resistance. Thus, thecontent of copper in the component body 2 is preferably 75 wt % or more.Furthermore, since copper is generally used for electrical wires and thelike, copper wires having various linear diameters are easily available.For this reason, for example, when a slide zipper having a big size isproduced, the component body 2 may be made of pure copper (the contentof copper is 100 wt %).

Meanwhile, as the ratio of zinc ingredients included in the componentbody 2 (metal body) is increased, the production costs may be decreased.However, there is concern that the corrosion resistance of the componentbody 2 may be reduced to cause the occurrence of stress corrosioncrevicing. For this reason, the content of zinc in the component body 2is preferably 25 wt % or less.

Furthermore, when the metal body (metal matrix) of the component body 2is made of zinc or a zinc-based alloy, complicated shapes such as aslider, an insert pin, a box pin, and the like may be readily andmassively formed by using a die-cast molding inexpensively. Meanwhile,zinc or the zinc-based alloy tends to be left behind in terms ofcorrosion resistance. For this reason, in the component body 2, a baseplating film made of copper having excellent corrosion resistance on thesurface of a metal body made of zinc or a zinc-based alloy is formed byusing electrolytic plating and the like.

Further, when the metal body (metal matrix) of the component body 2 ismade of an aluminum-based alloy (specifically, analuminum-magnesium-based alloy or an aluminum-copper-silicon-basedalloy), the weight of the zipper component 1 may be readily reduced.Meanwhile, the aluminum-magnesium-based alloy oraluminum-copper-silicon-based alloy tends to be left behind in terms ofcorrosion resistance, and thus anti-corrosion treatment is required. Forthis reason, in the component body 2, a first base plating film made ofzinc is first formed on the surface of a metal body made of analuminum-based alloy by using electroless plating and the like, and thena base plating film made of copper having excellent corrosion resistanceis formed on the surface of the first base plating film by usingelectrolytic plating and the like.

In addition, when the metal plating film 3 is subjected to thermaltreatment to be described below, the component body 2 of the embodimenthas the diffusion layer 4 formed by diffusing the metal included in themetal plating film 3 in the surface layer portion of the component body2.

When the metal matrix of the component body 2 is made of, for example,copper or a copper-zinc-based alloy, the diffusion layer 4 is formed onthe surface layer portion of the component body 2 (metal body) made ofcopper or a copper-zinc-based alloy. Furthermore, when the metal body ofthe component body 2 is made of, for example, zinc or a zinc-basedalloy, the diffusion layer 4 is formed on the surface layer portion ofthe base plating film made of copper which is provided on the surface ofthe metal body. Further, when the metal body of the component body 2 ismade of, for example, an aluminum-based alloy, the diffusion layer 4 isformed on the surface layer portion of a second base plating film madeof copper which is provided on the side nearest to the surface of thecomponent body 2.

Since the diffusion layer 4 is formed on the surface layer portion ofthe component body 2 so that the metal plating film 3 may have goodaffinity to the component body 2, the adhesiveness of the metal platingfilm 3 on the component body 2 may be increased. In addition, forexample, when the component body 2 is made of a copper-zinc-based alloyand the metal plating film 3 is also made of a copper-zinc-based alloy,the diffusion layer 4 is not formed when the content of zinc included inthe component body 2 is higher than that included in the metal platingfilm 3.

In the zipper component 1 according to the embodiment, the metal platingfilm 3 is formed on the surface of the component body 2 as describedabove in order to impart a desired color tone to the zipper component 1.The metal plating film 3 is formed on the surface of the component body2 by first performing a wet or dry plating treatment as described below.In this case, the metal plating film 3 has a columnar crystal structurewhich is oriented on the (111) plane.

Furthermore, after the metal plating film 3 having the columnar crystalstructure is formed, the metal plating film 3 is subjected to thermaltreatment at a temperature which is equal to or more than therecrystallized temperature before the zipper component 1 is bent. Atleast a part of the columnar crystal structure is recrystallized by thethermal treatment, and thus a metal plating film 3, on which arecrystallized structure wherein the crystal orientation is not observed(the crystal orientation is disturbed) is formed, is constituted.

In this way, at least a part of the metal plating film 3 may have arecrystallized structure, as described above, and thus the metal platingfilm 3 is softer than a metal plating film 3 having only a columnarcrystal structure and the metal plating film 3 may be readily diffused.

In the embodiment, for example, copper (pure copper), acopper-zinc-based alloy and a white-system metal (for example, acopper-tin-based alloy, a tin-nickel-based alloy, nickel, chromium,vanadium, rhodium, platinum and the like) may be used as a material forthe metal plating film 3.

In this case, if a metal body made of the metal matrix of the componentbody 2 is softened by a thermal treatment at a temperature of which arecrystallized structure may be formed in the metal plating film 3,there is concern that the zipper component 1 may be deformed. Therefore,the metal plating film 3 is made of a material which is the same as amaterial by which a recrystallized structure may be formed at atemperature less than that at which the metal matrix of the componentbody 2 is softened. For example, considering a color tone which ispreferred in the zipper component 1, a recrystallized temperature rangeof the metal plating film 3 and the like, the metal plating film 3 ispreferably made of at least one selected from the group consisting of acopper-zinc-based alloy, a copper-tin-based alloy and a tin-nickel-basedalloy.

In particular, when the metal matrix of the component body 2 is made ofcopper or a copper-zinc-based alloy, the metal plating film 3 formed onthe surface of the component body 2 is preferably made of, for example,a copper-zinc-based alloy (in particular, a brass having a zinc contentof 20 wt % or more) capable of imparting an antique style color tone ora copper-tin-based alloy or a tin-nickel-based alloy, which has a whitesystem color tone.

Further, when the metal matrix of the component body 2 is made of zinc,a zinc-based alloy or an aluminum-based alloy, the metal plating film 3formed on the surface of the component body 2 is preferably made of, forexample, a copper-zinc-based alloy (in particular, a brass having a zinccontent of 20 wt % or more) capable of imparting an antique style colortone.

In addition, the metal plating film 3 having a recrystallized structureof the embodiment have a film thickness of from 1 μm to 10 μm andpreferably from 2 μm to 6 μm. A metal plating film 3 may be stably andsecurely formed by setting the film thickness of the metal plating film3 to 1 μm or more (preferably 2 μm or more).

Meanwhile, the thicker the film thickness of the metal plating film 3 isformed, the metal plating film 3 may be stably formed. However, althoughthe film thickness of the metal plating film 3 is set at more than 10μm, the effect that the metal plating film 3 has been stabilized or theappearance quality obtained by the metal plating film 3 has beenimproved is not changed very much, and thus the film thickness of themetal plating film 3 is set at 10 μm or less (preferably 6 μm or lessand more preferably 3 μm or less).

In addition, the metal plating film 3 having the rescrystallizedstructure of the embodiment has a Vickers hardness of from Hv50 toHv100. When the Vickers hardness of the metal plating film 3 is Hv50 ormore, the occurrence of scratch and the like may be prevented on thesurface of the zipper component 1 and a good appearance quality may bemaintained. Meanwhile, when the Vickers hardness of the metal platingfilm 3 is Hv100 or less, the ductility of the metal plating film 3 maybe effectively improved.

Subsequently, the method for producing a zipper component 1 of theembodiment having the constitution as described above will be describedwith reference to FIG. 6.

First, a component body 2 having a predetermined shape is manufactured.For example, when the zipper component 1 is a metal zipper element 11 asdescribed above, the component body 2 of the metal zipper element 11(including a component body 2 before a base plating film is formed) ismanufactured by sequentially cutting a Y-shaped long metal wire into adesired thickness in the longitudinal direction to form an elementmaterial having a Y-shape when viewed from the front surface, subjectingthe element material to press molding to form a coupling head and thelike, or subjecting a plate material made of a metal such as copper, acopper alloy and the like, having a predetermined thickness, to pressmolding to form a coupling head and the like, and punching the platematerial.

Furthermore, when the zipper component 1 is a lower stopper 12, thecomponent body 2 of the lower stopper 12 is manufactured by sequentiallycutting a X-shaped or a H-shaped long metal wire into a desiredthickness in the longitudinal direction. When the zipper component 1 isan upper stopper 13, the component body 2 of the upper stopper 13 ismanufactured by sequentially cutting a long metal wire having a U-shapedcross section into a desired thickness in the longitudinal direction, orsequentially cutting a metal wire having a plate shape into a desiredthickness in the longitudinal direction and bending a cut fragmentobtained into a U-shape.

Further, when the zipper component 1 is a slider, an insert pin, a boxpin, or a slider 14, the component body 2 is manufactured by performinga die-cast molding using a metal mold having a predetermined cavityshape.

In addition, in the invention, a method or means for manufacturing acomponent body 2 is not particularly limited, and may be arbitrarilymodified depending on a material, a shape and the like of the zippercomponent 1.

In this case, when a metal body of the component body 2 is made of, forexample, zinc or a zinc-based alloy, a base plating film made of copperis formed on the surface of the metal body by electrolytic plating inorder to improve the corrosion resistance of the component body 2.Furthermore, when a metal body of the component body 2 is made of, forexample, an aluminum-based alloy (for example, analuminum-magnesium-based alloy or an aluminum-copper-silicon-basedalloy), a first base plating film made of zinc is formed on the surfaceof the metal body by electroless plating and a second base plating filmmade of copper is formed on the surface of the first base plating filmby electrolytic plating, in order to improve the corrosion resistance ofthe component body 2.

Successively, a component body 2 of the zipper component 1 ismanufactured as described above, and then the component body 2 issubjected to plating treatment to form a metal plating film 3 having acolumnar crystal structure on the surface of the component body 2. Inthis case, the metal plating film 3 formed on the surface of thecomponent body 2 is crystally grown in a columnar shape. Further, amaterial for the metal plating film 3 formed on the surface of thecomponent body 2 is not particularly limited, but as described above,the material is preferably composed of a copper-zinc-based alloy, acopper-tin-based alloy or a tin-nickel-based alloy.

In addition, in the embodiment, a method for forming the metal platingfilm 3 is not particularly limited, but any plating treatment of wet ordry plating treatments may be employed. For example, electrolyticplating, hot dipping and the like may be used as a wet platingtreatment, while a PVD method, a CVD method and the like may be used asa dry plating treatment.

Further, when a metal plating film 3 having a columnar crystal structureis formed, the metal plating film 3 is formed by setting the filmthickness of the metal plating film 3 at from 1 μm to 10 μm andpreferably from 2 μm to 6 μm. Furthermore, the Vickers hardness on thesurface of the metal plating film 3 formed in this way also variesdepending on the material of the metal plating film 3, but shows a valueof basically Hv120 or more.

Subsequently, the plating treatment is performed as described above, andthen the zipper component 1 on which a metal plating film 3 is formed issubjected to thermal treatment (recrystallized treatment) at atemperature which is equal to or more than the recrystallizedtemperature. In this case, when the metal plating film 3 of the zippercomponent 1 is made of, for example, a copper-zinc-based alloy, thethermal treatment is performed in a non-oxidizing atmosphere in atemperature range of from 300° C. to 400° C. for a predetermined time.

The metal plating film 3 may be prevented from being oxidized during thethermal treatment by performing the thermal treatment in a non-oxidizingatmosphere. In this case, as the non-oxidizing atmosphere, a nitrogengas atmosphere, an argon gas atmosphere, a carbon monoxide gasatmosphere, vacuum atmosphere and the like may be used. Further, arecrystallized structure wherein a columnar crystal structure isrecrystallized may be readily and stably formed in at least a part ofthe metal plating film 3 made of a copper-zinc-based alloy by performingthe thermal treatment in a temperature range of from 300° C. to 400° C.,and the component body 2 may also be prevented from being softened.

In addition, when the metal plating film 3 is made of, for example, acopper-tin-based alloy, the thermal treatment is performed in apressurized non-oxidizing atmosphere in a temperature range of from 400°C. to 500° C. for a predetermined time. Meanwhile, when the metalplating film 3 is made of a tin-nickel-based alloy, the thermaltreatment is performed in a pressurized non-oxidizing atmosphere in atemperature range of from 500° C. to 600° C. for a predetermined time.

In this way, the thermal treatment may be performed in a pressurizednon-oxidizing atmosphere of, for example, 0.1 MPa or more (preferably0.5 MPa or more) to prevent tin included in the metal plating film 3from evaporating during the thermal treatment and prevent the metalplating film 3 from being oxidized. In this case, as the non-oxidizingatmosphere, a nitrogen gas atmosphere, an argon gas atmosphere, a carbonmonoxide gas atmosphere and the like may be used. In addition, arecrystallized structure may be readily and stably formed in at least apart of the metal plating film 3 by performing the thermal treatment ina predetermined temperature range.

The Vickers hardness on the surface of the metal plating film 3 may bereduced to from Hv50 to Hv100 and the ductility of the metal platingfilm 3 may be improved by performing the thermal treatment(recrystallized treatment) as described above to form a recrystallizedstructure wherein a columnar crystal structure is recrystallized in atleast a part of the metal plating film 3. Furthermore, the thermaltreatment is performed to form a diffusion layer 4 from diffusion of themetal included in the metal plating film 3 into the surface layerportion of the component body 2. Accordingly, the zipper component 1 inthe embodiment described above may be obtained.

Furthermore, the metal plating film 3 is made of a material which mayform a recrystallized structure at a temperature less than that at whichthe metal matrix of the component body 2 is softened. Therefore, eventhough the thermal treatment which recrystallizes the columnar crystalstructure of the metal plating film 3 in the zipper component 1 isperformed, the component body 2 is less likely to be softened and thestrength of the component body 2 is not reduced.

The thermal treatment (recrystallized treatment) is completed, and thenwhen the metal plating film 3 is made of a copper-zinc-based alloy,copper included in the metal plating film 3 may be oxidized toadditionally performed a blackening treatment (black oxide finish) whichimparts the black color to the metal plating film 3. Specifically, acupric oxide coating film is formed on the surface of the metal platingfilm 3 by immersing a zipper component 1 having the metal plating film 3in a strong alkali solution including sodium hydroxide and sodium andsodium chlorite.

Further, in the invention, the treatment conditions in the blackeningtreatment of the metal plating film 3 may be arbitrarily selecteddepending on the composition of an alloy which constitutes the metalplating film 3 and the like. In addition, means for blackening the metalplating film 3 are not particularly limited. Furthermore, in theinvention, the blackening treatment is not particularly limited to theblackening of the metal plating film 3 made of a copper-zinc-basedalloy, and a color of green or blue may be imparted to the metal platingfilm 3 by changing the color tone of the metal plating film 3 using, forexample, a copper sulfate method or a thiosulfate method.

Thereafter, the zipper component 1 which is blackened on the surface ofthe metal plating film 3 may be subjected to polishing treatment. Forexample, a zipper component 1 which has been subjected to blackeningtreatment is introduced into a barrel polishing machine along with apolishing material (polishing stone and the like) to perform polishingtreatment. Accordingly, a part of the blackened oxide coating film maybe peeled off to finish the surface of the zipper component 1 with anantique style old brass color. Further, in the polishing treatment, apolishing method such as shot blast and the like instead of the barrelpolishing may be used depending on the shape of the zipper component 1and the like.

Meanwhile, the above-described thermal treatment is performed and thenwhen the metal plating film 3 is made of a copper-tin-based alloy or atin-nickel-based alloy, the metal plating film 3 has a white-systemcolor tone. For this reason, the metal plating film 3 may be subjectedto polishing treatment such as barrel polishing, shot blast and the likeinstead of the blackening treatment as described above.

In addition, after the polishing treatment is completed, the obtainedzipper component 1 is washed with water and dried. Thereafter, a coatingtreatment which performs a transparent clear coating on the surface ofthe zipper component 1 for the purpose of protecting the surface of thezipper component 1, preventing discoloration and preventing corrosion.

The zipper component 1 manufactured after undergoing the treatmentprocess as described above is then subjected to bending such as caulkingand the like to be used as a slide zipper. In this case, the metalplating film 3 provided on the zipper component 1 has excellentductility because the metal plating film 3 has a recrystallizedstructure as described above. For this reason, even though the zippercomponent 1 is bent, the metal plating film 3 may be readily extended tofollow the deformation of the zipper component 1 by the bending.

Accordingly, even though the zipper component 1 is bent, it is difficultto generate crevicing or cracking in the metal plating film 3 andfurthermore crevicing or cracking in the metal plating film 3 may not begenerated. In particular, for example, even when the zipper component 1has a big size and the deformation volume of the zipper component 1during the bending, the bending may be smoothly performed without theoccurrence of crevicing or cracking in the metal plating film 3.

For this reason, a problem in the related art, which is generated due tocrevicing or cracking in the metal plating film, for example, a problemthat a base material is exposed from crevicing or cracking in the metalplating film to visually deteriorate the zipper component, or a problemthat corrosion is easily generated on the base material of the zippercomponent may be readily solved.

Example 1

Hereinafter, the invention will be described in more detail withreference to specific Examples.

As Example 1, the case, in which a lower stopper 12 as shown in FIGS. 3to 5 is produced as a zipper component, will be described. The lowerstopper 12 of the present Example 1 has a component body made of purecopper and a metal plating film provided on the surface of the componentbody. In this case, the metal plating film is made of an alloy of copperand zinc, which has a copper content of 65 wt % and a zinc content of 35wt %.

In order to produce the lower stopper 12 of the present Example, a longpure copper wire having a circular cross-section is first subjected tocold rolling to deform the cross-section of the pure copper wire into anH-shape. Successively, the component body of the lower stopper 12 ismanufactured by cutting the pure copper wire having a H-shapedcross-section into a desired thickness in the longitudinal direction.Thereafter, the obtained component body was subjected to barrelpolishing treatment to remove burrs formed on the component body.

Subsequently, the component body of the lower stopper 12 manufacturedwas subjected to plating treatment by electrolytic plating under apredetermined condition to form a metal plating film of acopper-zinc-based alloy on the surface of the component body. Moreover,the metal plating film is formed, and then the cross-section of themetal plating film was observed by transmission electron microscope(TEM). As a result, it was confirmed that the metal plating film formedwas crystally grown on a columnar shape and the film thickness of themetal plating film was 5.2 μm.

Further, as a result of analyzing the metal plating film formed by X-raydiffraction (XRD), it was confirmed that the metal plating film isstrongly oriented on the (111) plane. In addition, as a result ofanalyzing the metal plating film by EPMA, it was confirmed that in themetal plating film, a region where copper and zinc were mixed in adifferent concentration ratio was formed. Furthermore, the Vickershardness of the metal plating film was measured, and thus the metalplating film was found to have a Vickers hardness of Hv160.

Subsequently, a lower stopper 12 having a metal plating film of acopper-zinc-based alloy formed on the surface of the component body madeof copper is subjected to thermal treatment (recrystallized treatment).In the thermal treatment, the lower stopper 12 was heated under vacuumat 380° C. for 1 hour. After the thermal treatment is completed, thecross-section of the metal plating film that the lower stopper had wasobserved by transmission electron microscope (TEM). As a result, it wasconfirmed that a columnar crystal structure observed in the thermaltreatment was lost and had a recrystallized structure wherein thecolumnar crystal structure is recrystallized.

In addition, in the TEM observation, it was confirmed that the filmthickness of the metal plating film appeared to be increased from 5.2 μmto 8.0 μm. Therefore, the metal plating film was analyzed by EPMA, andthus it was confirmed that a diffusion layer wherein zinc included inthe metal plating film was diffused in copper of the component body wasformed in the area in which the film thickness of the metal plating filmwas increased. From this result, it is determined that the diffusionlayer is formed on the surface layer portion of the component body andthus the film thickness of the metal plating film appeared to beincreased in the TEM observation.

Furthermore, as a result of analyzing the metal plating film which hadbeen subjected to thermal treatment by X-ray diffraction (XRD), theorientation on the (111) plane was lost and the crystal orientation wasnot observed. From this result, it was confirmed that the metal platingfilm had a recrystallized structure wherein a columnar crystal structurehad been recrystallized. Further, the Vickers hardness of the metalplating film after the thermal treatment was measured, and thus it wasconfirmed that the metal plating film had a Vickers hardness of Hv80 andthe Vickers hardness of the metal plating film was reduced by thethermal treatment.

Subsequently, a blackening treatment which imparts the black color tothe metal plating film was performed by immersing the lower stopper 12which had been subjected to thermal treatment in a strong alkalisolution including sodium hydroxide and sodium chlorite. Thereafter, thecolor tone of the lower stopper 12 was finished with an antique styleold brass color by performing polishing treatment on the lower stopper12 which had been subjected to a blackening treatment using a barrelpolishing machine, and then the lower stopper 12 was subjected to aclear coating treatment.

After the clear coating treatment is completed, the lower stopper 12obtained was subjected to bending to mount the lower stopper 12 on thezipper tape 15 (see FIGS. 4 and 5). Moreover, the surface of the lowerstopper 12 mounted on the zipper tape 15 was observed with the nakedeye, and crevicing or cracking in the metal plating film of the lowerstopper 12 was not observed and the lower stopper 12 had good appearancequality which uniformly exhibited the antique style color tone.

Meanwhile, in order to confirm the effects of the lower stopper in thepresent Example 1, a lower stopper is produced under the same conditionsas in Example 1, except that the thermal treatment was not performedafter the metal plating film was formed (Comparative Example), and thenthe lower stopper was mounted on the zipper tape by caulking the lowerstopper. Moreover, the surface of the lower stopper according toComparative Example, which was mounted on the zipper tape, was observedwith the naked eye, and then crevicing or cracking had beensignificantly generated in the metal plating film of the lower stopper.In addition, crevicing or cracking formed in the metal plating film isinterposed in the lower stopper to expose a base metal matrix and thuswas visually left behind (in terms of appearance quality).

Example 2

As Example 2, the case, in which a metal zipper element 11 is producedas a zipper component, will be described. The metal zipper element 11 ofthe present Example 2 has a component body made of an alloy (brass) ofcopper and zinc and a metal plating film provided on the surface of thecomponent body. In this case, the alloy constituting the component bodyhas a copper content of 85 wt % and a zinc content of 15 wt %.Furthermore, the metal plating film is made of an alloy of copper andtin, which has a copper content of 70 wt % and a tin content of 30 wt %.

In order to produce the metal zipper element 11 of the present Example2, a coupling head and the like are formed by subjecting a platematerial made of brass, which has a predetermined thickness to pressmolding, and a component body of the metal zipper element 11 ismanufactured by punching the plate material. Thereafter, the obtainedcomponent body was subjected to barrel polishing treatment to removeburrs formed on the component body.

Subsequently, the component body of the metal zipper element 11manufactured was subjected to plating treatment by electrolytic platingunder a predetermined condition to form a metal plating film of acopper-zinc alloy on the surface of the component body. Thereafter, themetal zipper element 11 on which the metal plating film was formed wassubjected to thermal treatment (recrystallized treatment). In thethermal treatment, the metal zipper element 11 was heated in apressurized argon gas atmosphere of 0.6 MPa at 430° C. for 1 hour.

Successively, the metal zipper element 11 which had been subjected tothermal treatment was subjected to clear coating treatment. Thereafter,the metal zipper element 11 was mounted on the zipper tape 15 bycaulking the metal zipper element 11 which had been subjected to clearcoating. Moreover, the surface of the metal zipper element 11 mounted onthe zipper tape 15 was observed with the naked eye, and thus it wasconfirmed that crevicing or cracking was not generated in the metalplating film.

Example 3

As Example 3, the case, in which a box pin is produced as a zippercomponent, will be described.

The box pin of the present Example 3 has a component body made of azinc-based alloy as a metal matrix and a metal plating film provided onthe surface of the component body. In this case, the component body hasa metal body made of a zinc-based alloy and a base plating film made ofcopper, which is formed on the surface of the metal body. Further, themetal plating film is made of an alloy of copper and zinc, which has acopper content of 65 wt % and a zinc content of 35 wt %.

In order to produce the box pin of the present Example 3, a metal bodyfor a box pin having a predetermined shape was first formed bysubjecting zinc to a die-cast molding. Successively, a component body ofthe box pin was manufactured by subjecting the obtained metal body toelectrolytic plating under a predetermined condition to form a baseplating film made of copper on the surface of the metal body.

Subsequently, the component body of the box pin manufactured issubjected to plating treatment by electrolytic plating under apredetermined condition to form a metal plating film of acopper-zinc-based alloy on the surface of the component body.Thereafter, the box pin on which the metal plating film was formed wassubjected to thermal treatment (recrystallized treatment). In thethermal treatment, the box pin was heated in a pressurized atmosphere of0.6 MPa at 320° C. for 1 hour.

Successively, a blackening treatment which imparts the black color tothe metal plating film was performed by immersing the box pin which hadbeen subjected to thermal treatment in a strong alkali solutionincluding sodium hydroxide and sodium chlorite. Further, the color toneof the lower stopper was finished with an antique style old brass colorby performing polishing treatment on the box pin which had beensubjected to a blackening treatment using a barrel polishing machine,and then the box pin was subjected to a clear coating treatment.

Thereafter, the box pin was mounted on the zipper tape by caulking thebox pin which had been subjected to clear coating. Moreover, the surfaceof the box pin mounted on the zipper tape was observed with the nakedeye, and thus it was confirmed that the box pin generally had a uniformcolor tone and crevicing or cracking was not generated in the metalplating film.

Example 4

As Example 4, the case, in which a slider body for a slider 14 isproduced as a zipper component, will be described. The slider body ofthe present Example 4 has a component body made of analuminum-copper-silicon-based alloy as a metal matrix and a metalplating film provided on the surface of the component body.

In this case, the component body has a metal body made of analuminum-copper-silicon-based alloy, a first base plating film of zinc,which is formed on the surface of the metal body, and a second baseplating film of copper, which is formed on the surface of the first baseplating film. In addition, the metal plating film is made of an alloy ofcopper and zinc, which has a copper content of 65 wt % and a zinccontent of 35 wt %.

In order to produce the slider body of the present Example 4, a metalbody having a predetermined shape was first formed by subjecting thealuminum-copper-silicon-based alloy to a die-cast molding. Successively,a component body of the slider body was manufactured by subjecting theobtained metal body to elecroless plating under a predeterminedcondition to form a first base plating film of zinc on the surface ofthe metal body and by subjecting the obtained metal body to electrolyticplating under a predetermined condition to form a second base platingfilm made of copper on the surface of the first base plating film.

Subsequently, the component body of the slider body manufactured issubjected to plating treatment by electrolytic plating under apredetermined condition to form a metal plating film of acopper-zinc-based alloy on the surface of the component body.Thereafter, the slider body on which the metal plating film was formedwas subjected to thermal treatment (recrystallized treatment). In thethermal treatment, the slider body was heated under vacuum at 330° C.for 1 hour.

Successively, a blackening treatment which imparts the black color tothe metal plating film was performed by immersing the slider body whichhad been subjected to thermal treatment in a strong alkali solutionincluding sodium hydroxide and sodium chlorite. Furthermore, the colortone of the lower stopper was finished with an antique style old brasscolor by performing polishing treatment on the slider body which hadbeen subjected to a blackening treatment using a barrel polishingmachine, and then the slider body was subjected to a clear coatingtreatment.

Thereafter, a tab was attached to a tab mounting portion of the sliderbody which had been subjected to clear coating, and the tab was mountedon the slider body by bending the tab mounting portion. Moreover, thesurface of the slider body on which the tab was mounted by bending wasobserved with the naked eye, and thus it was confirmed that the sliderbody generally had a uniform color tone and crevicing or cracking wasnot generated in the metal plating film.

DESCRIPTION OF REFERENCE NUMERALS

-   1 Zipper component-   2 Component body-   3 Metal plating film-   4 Diffusion layer-   10 Slide zipper-   11 Metal zipper element-   12 Lower stopper-   12 a Body portion-   12 b Arm portion-   13 Upper stopper-   14 Slider-   15 Zipper tape-   15 a Core thread portion

1. A zipper component for a slide zipper, including: a metal platingfilm formed on the surface of a component body made of a metal; and atleast a part of the component body subjected to bending after the metalplating film is formed, wherein the metal plating film has arecrystallized structure in which at least a part of a crystal structurehas been recrystallized by performing thermal treatment before thebending.
 2. The zipper component according to claim 1, wherein therecrystallized structure is formed by forming the metal plating film asa columnar crystal structure on the surface of the component body, andthen subjecting the metal plating film to the thermal treatment torecrystallize at least a part of the columnar crystal structure.
 3. Thezipper component according to claim 1, wherein the component body ismade of copper or a copper-zinc-based alloy.
 4. The zipper componentaccording to claim 3, wherein the component body is made of copper in anamount of at least from 75 wt % to 100 wt % and zinc in an amount offrom 0 wt % and 25 wt %.
 5. The zipper component according to claim 1,wherein the component body has a metal body made of zinc or a zinc-basedalloy and a base plating film which is provided on the surface of themetal body and is made of copper.
 6. The zipper component according toclaim 1, wherein the component body has a metal body made of analuminum-based alloy, a first base plating film which is provided on thesurface of the metal body and is made of zinc, and a second base platingfilm which is provided on the surface of the first base plating film andis made of copper.
 7. The zipper component according to claim 1, whereinthe metal plating film is composed of at least one selected from thegroup consisting of a copper-zinc-based alloy, a copper-tin-based alloyand a tin-nickel-based alloy.
 8. The zipper component according to claim1, wherein the metal plating film having the recrystallized structurehas a film thickness of from 1 μm to 10 μm.
 9. The zipper componentaccording to claim 1, wherein the metal plating film having therecrystallized structure has a Vickers hardness of from Hv50 to Hv100.10. The zipper component according to claim 1, wherein the zippercomponent has a diffusion layer formed by diffusing a metal included inthe metal plating film in the surface layer portion on the metal platingfilm side of the component body.
 11. The zipper component according toclaim 1, wherein the zipper component is at least one component selectedfrom the group consisting of a zipper element, stoppers, an opening-typeseparable bottom end stop and a slider.
 12. A slide zipper, wherein thezipper component according to claim 1 is bent and used.
 13. A method forproducing a zipper component for a slide zipper, wherein a metal platingfilm is provided on the surface of a component body made of a metal andat least a part of the component body is subjected to bending after themetal plating film is formed, including: forming the metal plating filmon the surface of the component body; and subjecting the metal platingfilm to thermal treatment at a temperature which is equal to or morethan the recrystallized temperature before the bending to form arecrystallized structure in which at least a part of the metal platingfilm has been recrystallized.
 14. The method for producing a zippercomponent according to claim 13, including: forming the metal platingfilm provided on the surface of the component body as a columnar crystalstructure; and subjecting the metal plating film having the columnarcrystal structure to the thermal treatment to form the recrystallizedstructure.
 15. The method for producing a zipper component according toclaim 13, including: allowing the metal plating film to be made of acopper-zinc-based alloy; and heating the metal plating film to from 300°C. to 400° C. through the thermal treatment.
 16. The method forproducing a zipper component according to claim 13, including: allowingthe metal plating film to be made of a copper-tin-based alloy; andheating the metal plating film to from 400° C. to 500° C. through thethermal treatment.
 17. The method for producing a zipper componentaccording to claim 13, including: allowing the metal plating film to bemade of a tin-nickel-based alloy; and heating the metal plating film tofrom 500° C. to 600° C. through the thermal treatment.
 18. The methodfor producing a zipper component according to claim 13, including:controlling the Vickers hardness of Hv120 or more which the metalplating film has to from Hv50 to Hv100 through the thermal treatment.